MisoResearchAtOSU

This is a common experience, but interestingly one that I absolutely do not share. Some people report not feeling triggered by animals or babies, because "they don't know any better!" Whereas you can tell your wife about misophonia and their chip-eating might feel like a betrayal or intentional annoyance, your dog can't internalize that it bothers you. I think this experience helps to demonstrate that there's a social/contextual component to the condition, rather than just a pure auditory aversion.

Great questions!

1. There's not enough evidence currently to answer this question, but I'll speculate. While some researchers have proposed that associative learning is the mechanism by which misophonic triggers develop, I personally think there's more to the story. I'm not an expert in learning, but if that were the case it seems like everyone with misophonia should be able to point back to that moment in childhood where they had a negative association with chewing gum or clicking a pen, for example, and I know I certainly can't do that with (m)any of my triggers. Instead, I've seen in my own work that there are indeed "hardwired" neural differences in people with misophonia, at least as adults. Whether those differences exist from childhood and lead to misophonia or whether misophonia leads to those brain differences is still unknown currently. I'd love to do some longitudinal studies (following kids into adulthood) to better answer this question.
2. Disclaimer: I'm not a clinical psychologist, so take all this with a grain of salt. While exposure therapy might be helpful with certain phobias, I don't see its utility with misophonia, since misophonia is less of a "fear" to sounds and more of an "aversion/anger" toward sounds. In fact, I think a few case studies have tried exposure therapy and seen limited effects. There hasn't been a ton of research on treatments, but a few trials or case studies have reported benefit from cognitive behavioral therapy in their samples. Whether that's a treatment that works for everyone or whether the effects last long-term is still unknown.

This is a great question, but unfortunately the jury is still out. I think that's partially because up until recently, there hasn't been a solid consensus on how to define or assess misophonia, so its relationship with other disorders might look different depending on how you conceptualize what misophonia is.

Recently though, this work has come out demonstrating that about 35% of adults with Autism Spectrum Disorder also met criteria for "clinically significant misophonia" using a newly proposed diagnostic scale. I hope to see more validation/replication of this in the future.

I honestly have no idea. I actually use that exact point when I give talks on misophonia -- like sure, loud/rough sounds like nails on a chalkboard or screaming could have evolutionary benefits, but why am I bothered by these other particular sounds?! Maybe the lack of direct evolutionary benefit could be what distinguishes misophonic triggers from other sound sensitivities? Idk. But I think about this a lot.

This made me giggle, but I also fully understand the seriousness of this question.

I don't think this is uncommon. Voices and/or specific speech patterns (e.g., /s/, /k/, /t/ sounds, etc.) are often triggers for people. And misophonia triggers often feel worse when done by "close others" -- your mom, sister, roommate, etc. -- often people you can't immediately escape or whom you have to interact with frequently.